Oluwafemi Oluwafemi - 10 months ago 83
C# Question

How to enable CORS in ASP.NET Core

I am trying to enable cross origin resources sharing on my ASP.NET Core Web API, but I am stuck.


attribute accepts
of type
as parameter:

// Summary:
// Creates a new instance of the Microsoft.AspNetCore.Cors.Core.EnableCorsAttribute.
// Parameters:
// policyName:
// The name of the policy to be applied.
public EnableCorsAttribute(string policyName);

What does the
mean and how can I configure CORS on an ASP.NET Core Web API?

Answer Source

You have to configure a CORS policy at application startup in the ConfigureServices method:

public void ConfigureServices(IServiceCollection services)
    services.AddCors(o => o.AddPolicy("MyPolicy", builder =>

    // ...

The CorsPolicyBuilder in builder allows you to configure the policy to your needs. You can now use this name to apply the policy to controllers and actions:


Or apply it to every request:

public void Configure(IApplicationBuilder app)

    // ...